First, I think making a baby scream until they pass out is abusive. They need us, we should go to them. I have never made my sons CIO and they learned to sleep just fine.
Second, let her sleep in the car seat! My first son slept in it for 6 months and our pedi said that his kids both did almost as long:) It's totally safe and good for reflux if she's got it.
When he was almost six months old, he started sleeping longer, then one night he kept trying to climb out. We took the car seat out of the crib and laid him down thinking "this is going to be the longest night we've ever had" but it took him less than 10 minutes to fall asleep and he slept all night. She'll let you know when she's ready to not sleep in it. Just try every once in a while and if she cries for more than 5 minutes, put her back in the seat and try again in a couple weeks:)
On another note...DO NOT use Babywise. The author is a self-proclaimed baby expert, however no one else in the field agrees and he's not a doctor so he really doesn't have much experience other than with his own kids. His views on feeding are not only against AAP standards but have been known to cause failure to thrive (in so many babies at his own church he was kicked out!!). He is a shady man with questionable advice based on little experience that is geared to bottle feeders, not nursers.
Here's info from ezzo.info - a site built to get the word out about how detrimental his parenting philosophies can be.
* Infant Feeding Concerns
The American Academy of Pediatrics and breastfeeding professionals have raised many concerns about the Ezzos' infant feeding advice as presented in Babywise and Preparation for Parenting.
* Child Development Issues
It is generally recognized that parents should balance requirements for obedience with age-appropriate expectations. Experienced parents as well as experts in child development find GFI's programs fall short in this area.
*Lack of expertise and credentials. The primary
authors of the material, Gary and Anne Marie Ezzo, are
self-proclaimed experts. Gary Ezzo has no background or
expertise in child development, psychology,
breastfeeding, or pediatric medicine, and holds neither
an associate's nor a bachelor's degree from any college;
his master of arts degree in Christian ministry was
granted through a program that awarded credit for life
experience in lieu of an undergraduate degree. Anne
Marie Ezzo worked only briefly as an R.N. decades ago.
It is unclear what, if anything, Babywise co-author Dr.
Robert Bucknam contributed to that book, since the
earlier religious versions are essentially the same with
additional material and do not have his name on the
cover.
*Risks for breastfeeding mothers and babies.
Breastfeeding on a parent-determined schedule (including
a "flexible routine" as it is called in Babywise) may
reduce a mother's milk supply and contradicts the
recommendations of the American Academy of Pediatrics
(AAP), which has stated, "The best feeding schedules are
the ones babies design themselves. Scheduled feedings
designed by parents may put babies at risk for poor
weight gain and dehydration."
*Poor breastfeeding information. Although it is presented
as authoritative, the breastfeeding information
presented in Babywise is inaccurate and substandard
(compare with the AAP Breastfeeding recommendations from
the 2005 AAP Policy Statement on Breastfeeding and the
Use of Human Milk).
*One Size Doesn't Fit All. All babies and mothers are
treated alike without any respect given for individual
differences in breastmilk storage capacity, rate of milk
synthesis, rate of infant metabolism or stomach
capacity. In actuality, the number of feedings one
mother's body requires in order to supply her baby with
plenty of milk each day will be quite different from
other mothers around her. Similarly, breastfed babies
need varying amounts milk in varying numbers and sizes
of feedings, and they do not feed exactly the same way
from one feeding to the next in any case. Ezzo seemingly
expects all babies to respond in an identical manner.
This is no more realistic than expecting adults to
consume the same amounts of food on the same schedule
and grow (or lose weight!) at the same rate.
* Voices of Experience
The authors claim millions of success stories and
have many supporters, but many families who initially
considered their experience a success have reconsidered
the value of what they learned when problems developed
or as they became more experienced parents.